[1]张佩佩,张文太,贾宏涛,等.新疆北部地区与其他地区变性土壤线性膨胀系数的差异及矿物学机制[J].南京农业大学学报,2017,40(6):1074-1080.[doi:10.7685/jnau.201702018] ZHANG Peipei,ZHANG Wentai,JIA Hongtao,et al.Differences of coefficient of linear extensibility of vertic soils in northern Xinjiang and other regions of China and the mineralogical mechanism[J].Journal of Nanjing Agricultural University,2017,40(6):1074-1080.[doi:10.7685/jnau.201702018]

[Objectives] To explore the dominant factors affecting vertic characteristics of vertic soils, clay content and mineral composition were compared among suborders of vertisols.[Methods] Northern Xinjiang is the main distribution area of Xererts (including vertic soils), and we analyzed 14 soil pedons of vertic soils from northern Xinjiang, and collected data of 140 vertic soil profiles from 12 provinces of China. Data of coefficient of linear extensibility (COLE), clay content and smectite were analyzed.[Results] COLE, contents of clay and smectite of Xererts (including vertic soils)were the lowest in the five suborders and the swelling and shrinking characteristics of soils in northern Xinjiang were mainly affected by the higher illite-smectite mixing layer content. The other four suborders had more obvious vertic properties than Xererts (including vertic soils). Contents of clay and smectite of Aquerts, Underts and Xererts (including vertic soils)at 0-100 cm were higher than those at 0-30 cm, while the case for Usterts was just in contrary. With increasing depth, clay and smectite did not change significantly for Cryerts. Smectite content of Aquerts was significantly higher than those of Usterts and Xererts (including vertic soils), and COLE value at 0-100 cm soil layer was significantly higher than that of Xererts (including vertic soils). However, COLE values of the five suborders were not significantly different at surface. With increasing of COLE of Aquerts, clay content and smectite content of Usterts increased and the change of surface smectite was linearly related with COLE.[Conclusions] Illite-smectite mixing layer content and smectite content of Xererts (including vertic soils)in northern Xinjiang were the intrinsic factors of soil vertic characteristics, while smectite content was closely related to clay content. Clay mineral composition plays a decisive role in controlling swelling and shrinking of surface’s vertisols.